GFCI all over the house

[jro]

Re: GFCI all over the house

Pierre despard is a type of interchangeable device , Example: recptacle, switch, made by Eagle and Pass & Seymour

 

[c-h]

Re: GFCI all over the house

Charlie,

Let's not loose sight of the fact that a GFCI is set for the range of 4 to 6 mA and may not protect the young, old, infirm, and small people from electrocution. The threshold is high enough to prevent nuisance tripping and to protect normal sized, healthy adults.

I feel you are exaggerating the danger, even if you have a point. The graph below is based on IEC 60479, Effects of current on human beings

This applies to adults. The 'b' curve is the current where some people loose control over their muscles. The 'c1' curve is the limit where some people start getting heart problems. (The 'c2' and 'c3' indicate 5% and 50% of people respectively)

The effect of the current is more severe the smaller/lighter the victim is. Obviously, a child will be much more sensitive than an adult.

However, the GFCI will still protect the child if the current is above the threshold of the device.

This forms the basis of the European view on GFCI protection: 30mA devices are used for protection people. It is considered sufficient to save those who have a current greater than this going through them. The number of people being killed by currents too low to affect the heart, but high enough to render them unable to get away from the current is too low to be an issue.

In North America the lower voltage (120V vs 230V) means that this risk is greater and consequently the GFCI's are designed to trip at 6mA or less.

It has been mentioned before but I don't think you are picking up on the fact that a shock will be delivered before the device trips, if it trips.

The current the human body can survive depends on the time it is exposed to it. The GFCI is designed to trip very fast. I don't have the data for an American device, but the types sold here in Europe typically trip in 40ms. For this very short period of time, the body can survive a significant current. If you look at the graph above, an adult will survive 500mA or more.

I would encourage the orginal poster to install GFCIs. It will make his children significantly safer, although teaching them respect for electricity is the most important safety measure.

[ June 29, 2003, 11:01 AM: Message edited by: c-h ]

 

[iwire]

Re: GFCI all over the house

Originally posted by c-h:
I would encourage the orginal poster to install GFCIs.

C-H no doubt you have seen me post on other forums pushing for GFCIs in more locations, and if someone wants to do their whole house that's great.

My fear here is that some people will think "Oh that's GFCI protected so it is not possible to get a fatal shock".

Remember that the GFCI will not trip for hot to neutral shocks.

IMO the money would be better spent on child safety covers to prevent accidental contact with any live parts in the first place.

Your comment

It will make his children significantly safer

Is only true if the child is grounded, this is not likely in most rooms of the house and as you know the GFCI will still not prevent a shock, it will just limit the duration.

I have a two and four year old and I would want to protect them from getting any shock no matter how short.

In my kids rooms the power to the outlets has been cut off, the ceiling light is enough for now.

So if you feel better with GFCIs great, but do not think that this makes your children safe from fatal shocks.

[ June 29, 2003, 07:24 PM: Message edited by: iwire ]

 

[c-h]

Re: GFCI all over the house

My fear here is that some people will think "Oh that's GFCI protected so it is not possible to get a fatal shock". Remember that the GFCI will not trip for hot to neutral shocks.

A fear that I share. Great care must be taken in the marketing of these.

IMO the money would be better spent on child safety covers to prevent accidental contact with any live parts in the first place.

Only if you have to choose between the GFCI and saftey covers. Why not both?

It remains a mystery why child safety shutters aren't integrated into all American receptacles. Were I live, shutters on the receptacles became standard long before grounding did. After the shutters came the safety collar and insulated sleeves. Both features prevent children (and careless adults) from touching the prongs when they are 'hot'. Many Swedish homes will have receptacles with shutters and safety collar but no grounding.

Many other countries have receptacles with various mechanism to protect the children, e.g. Australia and the UK.

Is only true if the child is grounded, this is not likely in most rooms of the house and as you know the GFCI will still not prevent a shock, it will just limit the duration.

Even if the risk of a lethal shock is reduced by 'only' 50%, I think it is worth the money.

Seat belts reduce the risk of being injured or killed in a car accident, but a certain risk still remain. That is not an excuse not to use them.